In 100 attacks:Mutilate does 167,665 damage to the target and grants 243 Combo points.Backstab does 155,580 damage to the target and grants 155 Combo points.

NOTE1: The above calculations do not include many talents, notably combat potency, surprise attacks, and relentless strikes.

NOTE2: The above calculations were written by someone that favors mutilate. The main issue would be what spec you would go to maximize backstab (full sub). I would like the original author to reproduce the calculations with the favorable talents included for backstab(20/0/41). The attack power and agility are both increased in sub, as well as 10% bonus to backstab, making crit and dps both higher on the base for backstab to compute these calculations. The difference of 8% that is achieved by these calculations lacking the 10% to AP, 15% to agi, 10% to backstab would clearly be over matched when added in, but then what does the effect of seal fate have on the calculations.

NOTE3: While it is true an all-out subtlety spec would increase the damage of backstab itself, the above calculations also fail to take into account a spec that is designed to optimize total damage output utilizing mutilate. Such a spec includes dual-wield specialization in the Combat tree, not only for its increase to Mutilate but for its increase to white damage as well. In short, for a raw comparison of the two abilities themselves in a situation where they're on approximately even footing, the above calculations are reasonably accurate (theory can only go so far.)